I don't think so. Novels have the power to transport us to different worlds, make us think, and touch our hearts. However, if expectations are too high or the genre isn't a match, one could have that perception.
Depends on who you ask. Some might find it overrated because it doesn't offer anything groundbreaking. But for others, it's a beloved Christmas classic that brings back fond memories.
Well, in some ways, Charizard can seem overrated in fanfiction. It's one of the most popular Pokemon, so a lot of writers might overuse it or give it too much power just because of its popularity. But on the other hand, it is a really cool and strong Pokemon, so it's understandable that it features a lot in fanfiction.
I think it depends. There are some amazing Harry Potter fanfictions that add depth to the universe and explore characters in new ways. However, there is also a large portion that is overrated. Some fanfictions go off on wild tangents that don't really fit with the essence of the original series. They might give Harry or other characters abilities that are completely out of character just for the sake of being different, and that's where the overrated aspect comes in.